1. Field of the Invention
The present invention relates to a laminated tube having a high logarithmic decrement of mechanical damping and flexural modulus and comprising layers, in a specified combination, of a composite material comprising a reinforcing fiber and a matrix resin.
The laminated tube of the present invention is light and excellent in vibration damping properties, mechanical strength and rigidity and is hence useful as tubing for portable apparatuses having power source, such as bush cutter, small vehicles such as bicycle and wheelchair, and the like.
2. Description of the Prior Art
Pipes of aluminum, which is relatively light among metals, are generally used as piping or tubing for articles requiring light weight and high mechanical strength and rigidity, e.g. portable apparatuses having power source, such as bush cutter, and small vehicles such as bicycle and wheelchair. For these items, however, there has been desired a lighter weight and reduction of vibrations transmitted from the power source or improvement of riding comfortableness. For example Japanese Patent Application Laid-open No. 170309/1986 proposes, for the tubing to be used for bush cutters, that comprising a composite material comprising a carbon fiber or glass fiber for reinforcement and a matrix resin.
It is true that the tubing comprising the above-proposed composite material is superior to aluminum tubing because of lighter weight and better vibration damping properties. There is, in some end-uses, however desired a pipe of still lighter weight and better vibration damping properties, and also for bush cutters lighter tube with still better vibration damping properties is desired for the purpose alleviating the burden that the operator should suffer.
For bush cutters, which often contact any surrounding object or the blade of which tends to be dragged into surrounding trees or the like during operation, the use of a tube having higher rigidity and impact resistance is also desired for improving the safety.
Accordingly, an object of the present invention is to provide a tube that has not only high mechanical strength and rigidity, but also markedly excellent vibration damping properties.